Field of the Invention
The present invention relates to a display device and a method of controlling the same.
Description of the Related Art
Conventionally, a plurality of projection display devices (hereinafter also referred to as projectors) are used in combination to project an image with a resolution and size that cannot be achieved using one projector; this technique is called multi-screen projection. In multi-screen projection, it is important to make a joint between images projected by different projectors appear less distracting. In view of this, a method called edge blending is known; with edge blending, input images and projection ranges are set so that, in an image joint area, identical images are displayed in an overlapping manner across a predetermined width, and the overlapping display area is dimmed to have brightness that is similar to brightness achieved in an area with no overlapping images. Edge blending can make a joint between projected images appear less distracting. Within an input image, an area that is to be displayed in an overlapping manner and to undergo dimming processing will hereinafter be referred to as an edge blending area.
Projectors may display, for example, a menu screen for settings as an on-screen display (OSD) screen. When an OSD screen is displayed using multi-screen projection, edge blending is applied to an input image on which an image of the OSD screen has been superimposed. In this case, if a display area of the OSD screen overlaps an edge blending area, the visibility of the OSD screen decreases in an overlapping area, and hence the usability of the OSD screen decreases.
To address this problem, Japanese Patent Laid-Open No. 2015-179940 discloses a method of preventing a reduction in the visibility of an OSD screen by moving a display area of the OSD screen to avoid overlap with an edge blending area.
In Japanese Patent Laid-Open No. 2015-179940, an edge blending area is set to span a wide range, and when overlap with the edge blending area cannot be avoided even by moving an OSD screen, the OSD screen is reduced in size. However, with such a size reduction, a reduction in the visibility of the OSD screen is inevitable. The need to reduce the size of the OSD screen may be eliminated by, for example, limiting a range in which the edge blending area can be set; however, in this case, the configurability of the edge blending area decreases.
Furthermore, although the visibility of an OSD screen could possibly be reduced by image adjustment other than edge blending, such as adjustment of the brightness and contrast of an entirety of projected images, the method disclosed in Japanese Patent Laid-Open No. 2015-179940 cannot address this issue. Therefore, a range in which image adjustment can be set is limited.